diff mbox series

[pushed] c++: -Waddress and value-dependent expr [PR105885]

Message ID 20220623150659.114599-1-jason@redhat.com
State New
Headers show
Series [pushed] c++: -Waddress and value-dependent expr [PR105885] | expand

Commit Message

Jason Merrill June 23, 2022, 3:06 p.m. UTC 
We already suppress various warnings for code that would be tautological if
written directly, but not when it's the result of template substitution.  It
seems we need to do this for -Waddress as well.

Tested x86_64-pc-linux-gnu, applying to trunk.

	PR c++/105885

gcc/cp/ChangeLog:

	* pt.cc (tsubst_copy_and_build): Also suppress -Waddress for
	comparison of dependent operands.

gcc/testsuite/ChangeLog:

	* g++.dg/cpp1z/constexpr-if37.C: New test.
---
 gcc/cp/pt.cc                                |  1 +
 gcc/testsuite/g++.dg/cpp1z/constexpr-if37.C | 21 +++++++++++++++++++++
 2 files changed, 22 insertions(+)
 create mode 100644 gcc/testsuite/g++.dg/cpp1z/constexpr-if37.C


base-commit: 8a15cd3396aa08dc2633982481fe392af0aa9e78
diff mbox series

Patch

diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc
index 80d2bec2348..4535c14c26a 100644
--- a/gcc/cp/pt.cc
+++ b/gcc/cp/pt.cc
@@ -20438,6 +20438,7 @@  tsubst_copy_and_build (tree t,
 	warning_sentinel s2(warn_div_by_zero, was_dep);
 	warning_sentinel s3(warn_logical_op, was_dep);
 	warning_sentinel s4(warn_tautological_compare, was_dep);
+	warning_sentinel s5(warn_address, was_dep);
 
 	tree r = build_x_binary_op
 	  (input_location, TREE_CODE (t),
diff --git a/gcc/testsuite/g++.dg/cpp1z/constexpr-if37.C b/gcc/testsuite/g++.dg/cpp1z/constexpr-if37.C
new file mode 100644
index 00000000000..e11e02cfa0e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/cpp1z/constexpr-if37.C
@@ -0,0 +1,21 @@ 
+// PR c++/105885
+// { dg-do compile { target c++17 } }
+// { dg-additional-options -Wall }
+
+int i;
+
+template<const char* ARG = nullptr>
+void test() {
+  if constexpr(ARG == nullptr) {
+    ++i;
+  } else {
+    --i;
+  }
+}
+
+const char CONSTSTR[] = {'\n', '\t', ' ', '\0'};
+
+int main() {
+  test();
+  test<CONSTSTR>();
+}